While Daniels appears to have avoided anything serious, Ryan and Brice might not have been as fortunate. One source said the Packers fear Ryan sustained a significant and potentially season-ending injury to his right knee. The injury occurred during an 11-on-11 drill late in practice. Ryan pounded his fist on the ground as he received medical attention.
Ryan was slated to start at inside linebacker next to Blake Martinez, who tied for the NFL lead in tackles last season.
"He was just devastated," Martinez said after practice. "Obviously, he was super-excited about the season. He's been putting a tremendous amount of work in. He's been awesome throughout OTAs and these past four practices. It's been good for him. It's just really tough.
"I talked to him right after I got off the field. Basically, told him if he needs anything, I'm here for him. I obviously don't know the extent of it. Obviously, everybody will know when they know. I'm just praying for him and hoping the best for him. I know he'll come back even stronger."
This could accelerate the need for rookie third-round pick Oren Burks to play a bigger role on defense. Also, defensive back Quinten Rollins has worked at inside linebacker in the sub packages, and the Packers are high on undrafted rookie linebacker Greer Martini of Notre Dame.
Meanwhile, Brice also had been working with the No. 1 defense and was perhaps the leading candidate to replace Morgan Burnett, who signed with the Steelers in free agency. Brice missed the final nine games of last season with a right ankle injury. It was unclear if Monday's injury was related.
He drew rave reviews from Packers coach Mike McCarthy this offseason.
"I think he's definitely having one of the best offseason programs," McCarthy said during the June minicamp. "The thing that goes unnoticed, and rightfully so from our perspective, is his communication skills. I love the way he plays. I think the ability to get past the injury and be here the whole time, having him full-go in the strength and conditioning program, you can see he's really comfortable out there with the adjustments and the communication. I would definitely be shocked if we're not sitting here after the season thinking that he's definitely taken a big jump, because I've seen it throughout the offseason."
Brice also was considered a strong candidate to play a major role on special teams. In fact, his injury occurred during a punting period in practice.
Second-year pro Josh Jones replaced Brice with the starters.
"Oh, man, that was bad," Jones said. "You hate to see that, especially as a player. That's your brother. You don't like to see an injury, period. I don't care who it is -- other teams, teammate, whatever. Everybody's got a family to feed, everybody's playing for something. You hate to see that."
The injuries tainted what to that point was perhaps the best day of camp for new coordinator Mike Pettine's defense. First-round pick Jaire Alexander picked off a Rodgers pass intended for Randall Cobb during the first team (11-on-11) period of the session, and safety Ha Ha Clinton-Dix came up with the other two interceptions -- one in the end zone to stop a 2-minute drill and another in a later team period.
In four practices, the defense has picked off Rodgers seven times -- not a sign that anything is wrong with the quarterback, but rather an indication that Pettine's new system has freed up defenders to make big plays.
In another injury-related note, running back Aaron Jones, who hasn't practiced since Friday because of a hamstring injury, said he expected to return this week.
The preseason is critical for Jones because he's suspended the first two games for violating the NFL's substance-abuse policy. Jones pleaded no contest to a marijuana-related charge in February, stemming from a traffic stop on Oct. 1 of last year.
Jones said he was surprised that his suspension was for two games. He said he lost an appeal to have it reduced.
"I was hoping it was one; it didn't happen," Jones said. "I'll just have to take the two games. I can't do anything about it but get ready for Week 3, finish training camp, come out healthy, play all four [preseason] games, and then Week 3, come out and be ready."